Grade crossing



J. A EISSES GRADE CROSSING Oct. 2, 1962 Filed Aug. 23, 1960 FIGJ iii I FIG.3

5 9 m m A E V wm O J PEEK:

AGENT FIG.4

States My present invention relates to a grade crossing between a railroad track and a highway, as described in my co-pending application Ser. No. 518,235, filed June 27, 1955 now abandoned of which the present application is a continuation-in-part, and to a method of constructing such crossing.

In some conventional grade crossings the rails are supported in spaced-apart relationship on a common base which also carries a set of spacing blocks or slabs level with the adjoining roadway. Since the slabs thus eifectively form part of the road surface, they tend to be depressed along with their supporting base by the passing vehicular traflic whereby the rails resting on the base are disaligned with respect to the main portion of the track. It is, therefore, the general object of the invention to provide a grade crossing of this type, capable of being quickly and conveniently installed, wherein the spacing slabs intermediate the rails are supported independently of the latter so that any settling of these slabs will not affect the position of the rails whereas, conversely, the rail traflic will not influence the road bed. A more particular object of the invention is to provide a grade crossing of the type specified whose components, after assembly, can be readily detached and removed for inspection, repair or replacement, as well as a method of so assembling these components as to enable their selective removal.

A feature of my invention resides in the provision of a pair of spaced-apart supports extending longitudinally of the track, each support preferably consisting of a series of adjoining pedestals carrying the respective rail, which are sunk in the ground and between them define a longitudinal channel receiving a bed of plastically deformable material, such as sand, whereon rest the inter-rail slabs advantageously along with suitable spacing members; the rails placed on these supports are interconnected by a series of generally transverse tie rods which are tensioned against the slabs and frictionally hold the latter in a position substantially level with the roadway sections terminating at the rails. The slabs pass around the tie rods with suflicient clearance to be able to move relatively thereto in a vertical direction; thus the slabs can settle on their supporing bed Without entraining the track unit composed of rails and tie rods and, furthermore, may be upwardly extracted (after a slight loosening of the rods) without any material displacement of the rails. The rail supports, at the same time, prevent any lateral spreading of the sand ballast or other slab-carrying material within its bed so that this material, after having been initially compacted by the slabs under load, will cease to yield andwill hold the slabs firmly in place; in practice it has been found suflicient to remove the slabs once, after an initial settling period of several months, and to add another layer of sand on the ballast bed whereupon the restored slabs will retain their position indefinitely.

The invention will be described in greater detail with reference to the accompanying drawing in which:

FIG. 1 is a top plan view of a grade crossing embodying the invention;

FIG. 2 is a fragmentary cross-sectional view of the crossing of FIG. 1, taken on the line IIII thereof but drawn to a larger scale;

FIG. 3 is a top plan view of the left-hand portion of the assembly shown in FIG. 2; and

FIG. 4 is a fragmentary sectional view taken on the line IV-IV of FIG. 2.

atcnt states The grade crossing shown in the drawing is inserted in a track consisting of a pair of rails 5 supported by transverse ties 6. In the region of the crossing these rails rest on respective supports formed by two rows of longitudinally adjoining pedestals 7 made of concrete.

Each pedestal 7, as best seen in FIG. 2, has a profile generally of inverted-T shape (right) or L shape (left) consisting of a base 7 and an upstanding ridge 7 The inner portion of the base 7 forms the carrying surface for the rail 5 while its outer portion acts as a support for one or more pavement blocks 18 which form part of the adjoining roadway and are level with both the ridge 7 and the rail. Also level with the rails and the roadway are a series of trapezoidal slabs 8 which rest between the rails on a ballast bed 20 of sand but do not bear upon the pedestals 7 except by their frictional connection with the rails 5 through the intermediary of spacers 12, this connection being established by means of tie rods 10 which pass between the slabs 8 and traverse the Webs of the rails against which they are tensioned by terminal nuts 11. The trapezoidal slabs 8 are undercut along their non-parallel sides to form recesses 9 which accommodate the tie rods 10 with sufficient clearance to permit a limited relative vertical motion between these rods and the slabs. The clamping force exerted upon the slabs 8 by the rods 10, through the intermediary of the spacers 12, is not strong enough to prevent such relative motion as the slabs slowly settle on the sand bed 20 under pressure of traffic, yet the extent of this settling movement of the slabs is limited by the restricted yieldability of the sand bed which is laterally confined between the bases 7' of pedestals 7.

Imbedded in each pedestal base 7 is a metallic anchor plate 17 with two upstanding ears 17 17 which straddle the lower flange of rail 5 and are traversed by respective spring clips 16 16 bearing upon that flange to hold the rail in position. The inner clip 16 resting against a plate 21 flush with the rail flange, is inserted at a location intermediate successive spacers 12 through the clearance formed between the top of rail 5 and the adjacent slab 8; to facilitate the insertion (and, if necessary, the removal) of the outer clip 16', the ridge 7 of pedestal 7 is provided with an access hole 7 in line with the clipreceiving aperture of car 17 The upper portion of each slab 8 is lined with angle irons 14 to protect it from chipping through contact with adjoining slabs and with the train wheels; its lower portion carries metallic abutment plates 15 making contact with the spacers 12.

The pedestal ridge 7 is also recessed to receive the ear 17 of anchor plate 17, as clearly seen in FIG. 2; the other ear l7 passes through a slot in a metal shelf 22 which supports the rail 5 on the inner step of the pedestal base 7 A layer 23 of sand or the like overlies the outer step of that base (right, FIG. 2) or rises directly from the ground (left) to the level of the adjoining ground which carries the roadway pavement. Moreover, the lateral faces of pedestal ridges 7 in line with the non-parallel sides of the slabs 8 are provided with semi-cylindrical recesses 7 which, complemented by similar recesses in adjoining slab faces, form sockets into which respective rods 10 with their terminal nuts 11 may be withdrawn, upon the removal of the opposite terminal nuts, whenever the removal of a rail section is desired. The voids alongside the rails 5 are occupied by a suitable plastic sealing mass 13, preferably asphalt, which is easily removable .for purposes of disassembly and into which the wheel flanges of the rolling stock will readily cut channels along the rails 5 as clearly seen in FIG. 2.

The trapezoidal configuration of the slabs 8 enables them to be positioned either with their bases alternately facing in opposite directions in conformity with a straight track section, as illustrated in FIG. 1, or with bases aligned along an arcuate track section as is well known per se.

In the installation of my improved grade crossing shown in the drawing, the first step is to excavate the ground along the outline shown in FIG. 2 to accommodate the pedestals 7 and the intervening sand ballast Ztl. Next, the Pedestals 7 are set in place within the excavation; thereupon the metallic track unit composed of rails 5, tie rods 1t) and spacers 12, held loosely together by the nuts 12, is lowered upon the bases 7 and aligned with the principal track. Now, the sand layers 20 and 23 are formed to support the slabs 8 and the pavement blocks 18 which are then positioned thereon; after these are properly leveled, the nuts 11 are tightened to tension the rods 10 against the slabs. Finally the asphalt mass 13 is cast to complete the assembly.

When, after an initial running-in period, the slab 8 have somewhat settled relatively to the rails and the pedestals 7, the asphalt mass 13 is partly removed to enable a loosening of the nuts 11 whereupon the slabs 8 may be extracted without materially disturbing the remainder of the assembly; a fresh layer of sand may now be deposited upon the bed 20, of a thickness sufficient to compensate for the difference in level, after which the process is reversed and the slabs are re-inserted and rejoined to the track. Naturally, the pavement blocks 13 may be similarly reset if they should have objecztionably settled on the sand layer 23; it will be understood, however, that this latter layer could also be omitted and the suitably shaped blocks 18 supported directly on the outer steps of bases 7 if the pedestal '7 is shaped as shown on the right in FIG. 2, or on the ground (with the type of slab shown on the left) if the terrain is firm enough to obviate the need for a firmer anchoring of the roadway to the crossing.

It will be apparent that, even with a narrow zone of the external roadway supported on an extension of the pedestal base directly or through a sand layer 23 as shown in the right-hand portion of FIG. 2, the rails 5 and their supporting pedestals 7 will be subjected at any time to only a fraction of the weight of road vehicles traversing the crossing and that, too, for only short periods. Substantially the full load of this vehicular traflic is borne, however, by the main roadway section of the crossing, constituted by the top surface of the large pavement blocks or slabs 8, which finds its own level substantially independently of the track unit 5, 10, 12 and the supports 7 thereof since it is supported independently therefrom on the sand foundation 20 and is joined to that unit by frictional forces only. Thus, rail traffic will remain unaffected even if the slabs should strongly buckle because of climatic conditions or for other reasons, yet any worn or improperly positioned slab may be readily extracted or readjusted by the technique described above. Moreover, the slabs 8 will not be materially displaced by any settling of the pedestals 7 and the rail sections 5 due to railborne traffic.

The invention is, of course, not limited to the precise details of construction and procedure herein disclosed but may be practiced in modified form without departing from the spirit and scope of the appended claims.

I claim:

1. A grade crossing between a railroad track and a roadway, comprising a pair of transversely spaced supports longitudinally extending below the track level at the intersection of the track with the roadway, a pair of rail sections respectively resting on said supports and forming part of said track, anchor means firmly securing said rail sections to said supports, respectively, tie means extending substantially transversely of said rail sections and interconnecting same at longitudinally spaced locations, a series of slabs extending between said rail sections intermediate said tie means with freedom of at least limited relative vertical motion between said slabs and said tie means, a foundation for said slabs located between said supports and independent of the latter, said supports and said foundation holding said rail sections and said slabs substantially at the level of adjoining roadway portions, said tie means maintaining said rail sections in only frictional contact with said slabs, and spacer means on said tie means interposed between said rail sections and said slabs, said rail sections being provided with bottom flanges resting on said supports, said anchor means comprising projections rising from said s pports adjacent said flanges at locations between said spacer means and clip means removably inserted in said projections in engagement with said flanges, each of said supports having an upstanding ridge extending alongside the respective rail section externally thereof, said clip means including inner and outer clips on opposite sides of each rail section, said ridge being apertured in line with said outer clips for enabling removal of the latter.

2.. A grade crossing according to claim 1 wherein said slabs have contacting faces undercut below their surfaces and forming clearances around said tie means.

3. A grade crossing according to claim 1 wherein said foundation comprises a bed of plastically deformable material laterally confined between said supports.

4. A grade crossing between a railroad track and a roadway, comprising a pair of transversely spaced supports longitudinally extending below the track level at the intersection of the track with the roadway, a pair of rail sections provided with bottom flanges respectively esting on said supports, said rail sections forming part of said track, each of said supports having an upstanding ridge extending along-side the respective rail section externally thereof, tie means extending substantially transversely of said rail sections and interconnecting same at longitudinally spaced locations, a series of slabs extending between said rail sections intermediate said tie means, a foundation for said slabs located between said supports, said supports and said foundation holding said rail sections and said slabs substantially at the level ot adjoining roadway ortions, spacer means on said tie means held by the latter under pressure between said rail sections and said slabs, projections rising from said supports adjacent said flanges at locations between said spacer means, and clip means removably inserted in said projections in engagement with said flanges for detachably anchoring said rail sections to said supports, said clip means including inner and outer clips on opposite sides of each rail section, said ridge being apertured in line with said outer clips for enabling removal of the latter.

5. A grade crossing between a railroad track and a roadway, comprising a pair of transversely spaced supports longitudinally extending below the track level at the intersection of the track with the roadway, a pair of rail sections respectively resting on said supports, anchor means removably securing said rail sections to said supports, said rail sections forming part of said track, each of said supports having 'an upstanding ridge extending alongside the respective rail section externally thereof, a plurality of tie rods extending substantially transversely of said rail section-s and interconnecting same at longitudinally spaced locations, a series of slabs extending between said rail sections intermediate said tie rods, and a foundation for said slabs located between said supports, said supports and said foundation holding said rail sections and said slabs substantially at the level of adjoining roadway portions, at least one of said ridges being provided with sockets accommodating the ends of respective tie rods upon withdrawal thereof from the remote rail section whereby the latter may be removed.

6. A grade crossing according to claim 5 wherein each of said supports comprises a series of longitudinally adjoining pedestals each having a rail-supporting base and an upstanding portion forming part of said ridge thereof, at least some of said pedestals having lateral ridge faces contacting each other in line with said tie rods and provided With complementary recesses together forming said sockets.

7. A grade crossing according to claim 5 wherein said slabs are of trapezoidal configuration, said tie rods extending along the non-parallel sides of the trapezoids. 5

References Cited in the file of this patent UNITED STATES PATENTS 6 Nichols Jan. 10, 1905 Burns July 18, 1916 Crofford July 24, 1917 Winter Sept. 17, 1918 Jones Aug. 31, 1926 Wooldridge Apr. 2, 1929 Young June 14, 1932 FOREIGN PATENTS Great Britain July 25, 1925 

